Reducing 'System Volume Information' file in Vista

I will apologise to begin with because I'm sure this topic will have been done to death here! -- but a search is not coming up with the answers I'm looking for.

My wife's laptop with Vista - we find that it has to be defragged every so often and this time I noticed that the SVI file was the one left with a lot of fragments, and a 7.5GB file size. I've done the initial homework and found how to get into 'admin', and how to run the "vssadmin" file. The file seems to be at "Allocated" size now though there is a "Max" figure shown of 10.25G

The instructions do tell me how to reduce the file size, but I'm not finding anyone saying what is a 'good' size, and whether it needs to be large. The laptop hard drive is partitioned into operating system ('C') and data ('D') with the 'C' drive about 30G, so currently this one file is taking 25% of the volume. I take it that the old Restore Points drop off the end when the file reaches its specified capacity.

The second question is whether I can move this file to the data drive as that has more capacity?

When you choose Apply the PC will reboot and the change will be made during the boot, outside of Windows. Once the PC reboots, you will see unallocated space where you just resized the partition. Now do the same with the C Drive except pull the left border to the end of the unallocated space.

Resizing your c drive to say 50 Gb should leave plenty of space for the OS and apps, especially if you move all data folders to the Data Drive.

If your Data Drive is sufficiently large you could even go up to about 75 Gb on the C Drive.

I've never had to use Restore Points in 20+ years of PC computing (all right they didn't exist that far back!!), but I get the feeling that this could be a hide/head/sand approach if I said they weren't important - so let's say I would rather hang on to them. I suppose in the end the question is how much space does one set of Points take up - or is that a long/string/how question?

Perhaps Medico's solution of adjusting the partition sizes may be the better, but that is also a hide/head/sand solution as it is just accepting what is going on. It also fails to address the problem of what impact the fragmenting of this file has on the drive.

You can check how much space you have allocated. If you have too much space, reduce it. You can also clear everything, the way I described and then create a new restore point. It will be there to use, if needed.